This proposed research will explore the possible link between an altered topological form of the PrP (called Ctm) and certain prion disease. Prion disease or spongiform encephalopathies are a novel class of neurodegenerative disorders that affect animals and humans. They include scrapie in sheep, bovine spongiform encephalopathy in cattle, as well as Creutzfeld-Jakob disease, Gerstmann-Straussler-Scheinker disease, fatal familial insomnia and kuru in humans. These diseases may occur sporadically, by genetic mutations, or acquired by transmission of an infectious agent. Protein aggregates and abnormal tissue deposits of normally soluble proteins have been found in the patients suffering from these diseases.